#include<iostream>
using namespace std;

int main()
{
	int n = 0;
	int sum = 0;
	int x = 0;
	cin >> n;
	for(int i = 1;i <= n;i++)
	{
		cin >> x;
		sum += x;
	}
	printf("%.2f",sum * 1.0 / n);
	return 0;
}
